Ryan Malloy
4dafbf8ce9
Implements row-decoding for IDS INTERVAL, the last common temporal type. The qualifier short bisects the type at the wire level: start_TU >= DAY maps to datetime.timedelta (day-fraction), start_TU <= MONTH maps to a new informix_db.IntervalYM (year-month). Wire format mirrors DATETIME exactly — `[head byte][digit pairs in base-100]`, with the qualifier dictating field interpretation. The fraction-to-nanoseconds scaling (`scale_exp = 18 - end_TU`, forced odd) is the JDBC pattern from `Decimal.fromIfxToArray`. IntervalYM is a frozen dataclass holding signed total months, with `years` and `remainder_months` as derived properties. Matches JDBC's `IntervalYM.months` shape rather than a (years, months) tuple — avoids ambiguity around what "negative" means for a multi-field tuple. Tests: 13 unit (synthetic byte streams covering all decoder branches) + 9 integration (real Informix queries spanning DAY TO SECOND, HOUR TO SECOND, YEAR TO MONTH, negatives, NULL, and mixed-family rows). Total test count: 53 unit + 82 integration = 135. Encoder for INTERVAL parameter binding is deferred to a later phase (same arc as DECIMAL/DATETIME — decode lands first).
informix-db
Pure-Python driver for IBM Informix IDS, speaking the SQLI wire protocol over raw sockets. No IBM Client SDK. No JVM. No native libraries.
Status
🟢 Phase 1 complete. connect() / close() work end-to-end against a real Informix server. Cursor / execute / fetch land in Phase 2.
To our knowledge this is the first pure-socket Informix driver in any language — every other Informix driver (IfxPy, the legacy informixdb, ODBC bridges, Perl DBD::Informix) wraps either IBM's CSDK or the JDBC JAR.
Quick start
import informix_db
with informix_db.connect(
host="127.0.0.1", port=9088,
user="informix", password="in4mix",
database="sysmaster", server="informix",
) as conn:
# cursor() / execute() / fetchone() arrive in Phase 2
pass
Test against the official Informix dev container
docker compose -f tests/docker-compose.yml up -d # IBM Developer Edition, pinned by digest
uv sync --extra dev
uv run pytest # 34 unit tests (no Docker needed)
uv run pytest -m integration # 6 integration tests (needs the container)
Phase 0 artifacts (still useful — they ARE the public reference)
docs/PROTOCOL_NOTES.md— byte-level wire-format reference, derived from packet captures + JDBC decompilation, validated against a real serverdocs/JDBC_NOTES.md— index into the decompiled IBM JDBC driver's wire-protocol classesdocs/DECISION_LOG.md— running rationale for protocol / auth / type decisionsdocs/CAPTURES/— socat hex-dump captures of three reference scenarios (connect, SELECT, full DML cycle)tests/reference/RefClient.java— re-runnable JDBC ground-truth client for capturing fresh traces
License
MIT.